Mineral dye and method of making same



Patented Mar. 21, 1939 I UNITED sTATas PATENT OFFICE Clarence a. White,Montclalr, N. J.

No Dravlng. Application august 2, 1931,,

Serial No. 150,951

10 Claims.

This invention relates, generally, to dyes, and

the invention has reference, more particularly, to

a novel mineral dye composition and the method of making the same, thesaid dyecomposition comprising essentially one or more chromium salts ofcarbohydrate acids, and being especially suitable for use either singlyor in admixture with additional ingredients for dyeing or ior printingtextile materials and the like;

Heretoiore, the only compound 01 chromium that could be satisfactorilyused in mineral dyeing of textile materials was chromous acetate and theuse-of this compound was attended with serious obstacles, among whichmay be mentioned the following: ilrstly, chromous acetate can only becompletely precipitated, as chromic hydroxide among the fibres of thetextile material treated, after long continued boiling with causticalkali, a condition which renders mass production quite impossible andresults in the bleeding" or dis-' persion of a portion of the chromousacetate, thereby weakening the resulting shade of the textile materialand rendering such shade variable or smeary; secondly, to avoidvariations in shade, it is necessary to put the dye saturated textilematerial through a highly expensive aging or oxidizing process duringwhich the textile material is treated with a mixture of high pressuresteam and atmospheric oxygen in an ager, wherein the chromous salt ispartiallyhydrolyzed and oxidized to a chromic state, in which conditionit is much more rapidly reactive in the presence oi caustic alkalies;and thirdly, chromous acetate can only be obtained in a condition oflimited concentration when in solution, i. e; about eight per cent ofchromium oxide, and this concentration more soluble chromic salts suchas the nitrate,

chloride, and sulphate of chromium, but these have not provenpracticable because of the tendency of the chromium salts to hydrolzeand set free the acid ions, which in turn tender or weaken thefabric.JI'his tendency, while it renders chromium salts invaluable as mordantsin the dyeing of wool, at the same time causes them to be useless in thedyeing of cotton. When a' cotton" fabric thus impregnated is-dried onthe cans, the chromic sulphate or chloride is decomposed, and sulphuricor hydrochloric acid, as the case may be, is liberated and rapidlytenders or even destroys thefabric.

a This application is a continuation, in part, of

my copending application for. Mineral dye and method of making same,filed January 14, 1935, Serial No. 1,701, Patent No.' 2,091,539.

The principal object ofthe present invention is to provide a dyecomposition comprising one or more compounds of chromium, whichcompounds overcome the above recited disadvantages of the knowncompounds of chromium, i. e. the compounds of this invention aresumciently soluble to permit a concentration great enough to insure theproper depth of shade with but a single dyeing, so that even or matchedshades are easily obtainable; the compounds of this invention aresuillciently reactive to the insolubilizing medium to permit theformation of the insoluble chromium dyeing compound immediately uponcontact with the insolubilizing bath, without bleeding out in the bath,thereby entirely eliminating the customary aging" process; and thecompounds of acid ions that will'tend to disintegrate the fabric whenthe same is dried on the cans.

Another objector the present invention lies in the provision of a novelchromium dye composition 01' the above character that is miscible withiron and other metallic salt dye liquors and which will not precipitateany such salts with which it is mixed, the said composition beingsuillciently stable when used alone or in conjunction with other mineraldyeliquors, so that no precipitation or clodding (clotting) or theformation of insoluble residues shall take place before or during theapplication of the dye liquor to'the fabric being processed.

Still another object of the present invention is to provide a novel dyecomposition of the above character that may be easily and cheaplyproduced on production basis.

Other objects of this invention, not at this time more particularlyenumerated, will be understood,

from the following detailed description of the same.

The novel composition of this invention comprises a mineral dye liquorconsisting essentially of one or more chromium salts of such carbohydricacids as gluconic, glucoronic, saccharic, glycolic and tri-hydroxybutyrlc acids, all 01' which are possible reaction products of thereaction of alkali bichromates on monosaccharoses in the presence ofhydrochloric and sulphuric acids, with or without association withcertain soluble fatty acids, e. g. acetic or formic acid, the sulphuricor hydrochloric acid being present in quantity sumcient to decompose thealkali bichromate, but not in suiiiclent quantity to form chromium saltswith the chromium'present in the alkali bichromate. These compounds canbe readily preparedin a condition of great concentration,

' this invention do not, upon hydrolyzing, set free exceeding undercertain conditions a content of 20% chromic oxide equivalent. Sodiumbichromate or potassium bichromate are preferably cheapness I prefer tomake use of cane sugar or sucrose, cane sugar molasses, beet sugar, beetsugar molasses, and black strap molasses or dextrine. All of thesematerials are classed as polysaccharoses, or polysaccharose compounds,and all are capable of being hydrolyzed by means of dilute acids intomonosaccharoses, or simple hexoses of either aldo-hexose or keto-hexosetype, or both. a

When a polysaccharose preparation of the desired chromium carbohydratecompound, it is, necessary that it be hydrolyzed into monosaccharoses bymeans of dilute acids. Polysaccharoses are divided into two classes:firstly, di-saccharoses or hexo-bioses, and also tri-saccharoses, whichare true sugars, and secondly, polysaccharoses that are not true sugars,such as starch, dextrine, amylose and cellulose. All of thepolysaccharoses, whether true sugars or not, are equally susceptible ofreduction by means of hydrolysis to mono-saccharoses or simple hexoses,and this hydrolysis or reduction is the first step of the invention.

-Cane sugar, with which may also be included cane sugar molasses,hydrolyzes into a molecule of glucose and a molecule of fructose, inaccordance with the following reaction:-

CHaOH-(CHOH) 4-CHO glucose (aldo-hexose) CHzOH-(CHOH) aCO-CH2OH fructose(keto-hexose) Upon oxidation, the aldehyde sugars (aldohexoses) yieldhydroxy mono-basic acids, and hydroxy di-basic acids of the same numberof carbon atoms. When a ketone sugar (ketohexose) is similarly oxidized,the original carbon chain is broken at the ketone group, and theresulting acids have a smaller number of carbon atoms than thecarbohydrate from which they were derived.

glucose (aldo-hex'ose) CHzOH-(CHOH) 4COOH gluconic acidpenta-hydroxy-hexan-oic acid CHzOH-(CHOH) 3COCH2OH+ O- is employed inthe chromium tri-hydroxy-butyrate and chromium glycolate.

Beet sugar molasses is an important raw material in the production ofchromium carbohydrate compounds, this material containing a largeproportion of the tri-saccharose, rafilnose. Upon hydrolysis, rafllnosesplits first into the monosaccharose (fructose, a keto-hexose) and adi-saccharose (melli-biose), which in turn hydrolyzes into glucose andgalactose, both aldohexoses. The range of chromium compounds producedwhen beet sugar molasses, or beet sugar, is employed are consequentlysimilar to the compounds produced when cane sugar (sucrose) is employed,because-in both cases an aldo-hexose and also a keto-hexose is oxidizedby .the alkali bichrornate.

The nomenclatin'e of the carbohydrates is somewhat vague, indefinite andinvolved. However, glucose is also known under the names dextrose, grapesugar and starch sugar, while fructose is also known as levuloseor fruitsugar. Maltose or malt sugar, and milk sugar or lactose are bothisomeric with sucrose or cane sugar, but maltose splits upon hydrolysisinto two molecules of glucose, while lactose splits into one molecule ofglucose and one 'molecule of galactose, both being aldo-hexoses.

The steps involved in the production of the mineral dye liquors that arethe subject of this invention are three in number:

1st. The hydrolysis and splitting of a polysaccharose into amonosaccharose (simple hexose) which is either a keto-hexose (e. g.fructose) 'or an aldo-hexose (e. g. glucose or galactose).

2nd. The oxidation of a keto-hexose or an aldo-hexose, or both, by meansof an alkali bichromate into a carbohydric acid. In the case of aketo-hexose, the resulting acids are, respectively, tri-hydroxy-butyrlcacid and glycolic acid,

and in the case of an aldo-hexose, gluconic acid,

capable'of further oxidation to saccharic acid.

3rd. The reaction by which a chromium compound of the carbohydric acidsproduced by the oxidation of the monosaccharoses (keto-hexoses andaldo-hexoses) is formed. The acids thus formed are gluconic, saccharic,tri-hydroxy butyric, and glycolic, which uniting with the contained,chromium form the glycolate, gluconate, tri-hydroxy-butyrate andsaccharate of chromium, respectively. I

In carrying out the processes of the present invention, I dissolve ormix in water to which from three to five per cent of hydrochloric orsulphuric acid has been added, a polysaccharose such asstarch dextrine,cane sugar, cane sugar molasses, beet sugar or beet sugar molasses, andthen digest the whole at a temperaturepreferably exceeding degrees,centigrade, maintaining this temperature until the polysaccharose hasbeen completely hydrolyzed and converted into simple monosaccharoses(aldo-hexose o'i' keto-hexose, or both, as the case may be). Additional.hydrochloric or sulphuric acid is now added to the completelyhydrolyzed solution in amount sumcient (molecular proportion) to breakdown the alkali bichromate to be later added. This addition is notcritical, it'be'ing possible to exceed this amount by from ten to twentyper cent, without thereby causing risk of damage to the goods to be dyedwith this liquor. This addition' completed, a quantity of an organicacid, preferably a soluble member of the fatty acid series. such asacetic or formic acid. is now added and the temperature of the whole israised to about '70 degrees, cent. The presence of the acetic, orequivalent acid, increases the solvent power of the resulting liquor forchromium salts, ensuring greater concentration, and at the same timestimulates the reaction that takesplace' The chromium trioxide at onceoxidizes the aldohexose present (glucose or galactose) to gluconic acid(CH2OH-(CHOH) 4-COOH), thereby being itself reduced to chromic oxide,which in turn reacts with the gluconic acidthat has been formed to formchromium gluconate. Where a keto-hexose (e. g. fructose) is present, thechromium trioxide ox dizes such keto-hexose into a molecule of glucolicacid (COOl'-ICH=OH) and an additional molecule of tri-hydroxy-butyricacid (CH2OH- (CHOH) 2-COOH) both of which acids react with the chromicoxide to form the tri-hydroxy-butyrate and the glycolate of chromium,respectively.

As specific examples of the actual manufacture of the mineral dyecomposition of this invention, the following ingredients are employed inthe proportions given by weight.

\ Pounds (1) Cane sugar or beet sugar 100 Water 620 Sulphuric acid 100to 110 Acetic acid '75 Sodium bi-chromate 300 or (2) Cane sugar, or beetsugar molasses 150 Water 620 Sulphuric acid 100 to 110 Acetic acid 75Sodium bi-chromate 300 Inasmuch as the above carbohydrates are convertedby hydrolysis into aldo-hexoses and also keto-hexoses, the chromiumcompounds formed will comprise glycolate, tri-hydroxy-butyrate andgluconate of chromium.

The above materials hydrolyze asaldo-hexoses,

' mostly glucose, and the chromium compounds produced will be mostlygluconate of chromium.

In carrying out the process of manufacture of the dye composition, I add35 pounds of sulphuric acid (or its molecular equivalent of hydrochloricacid) to about '75 gallons ('620 lbs) of water and into this acidsolution I mix or dissolve the stated amounts of the respectivecarbohydrates mentioned above (cane sugar and molasses, beet sugar andbeet molasses, dextrine, starch or corn syrup) or other suitablecarbohydrate compound. These compounds may be employed separately, orthey may be mixed, e. g.

cane sugar and cane molasses, cane sugar and beet molasses or glucose,etc. I then heat the resulting solution to a temperature of at least70.degrees, cent., maintaining the temperature at or above this figureuntil the carbohydrate has been hydrolyzed and converted into itsappropriate hexose or monosaccharose. The time required for thisconversion will vary in accordance,

with the carbohydrate used as the basic raw material, being relativelylong in the case of starch (one to three hours), and much shorter in thecase of cane sugar, and other true sugars.

At this Stage the remaining sixty-five pounds of sulphuric acid (or itsmolecular equivalent in hydrochloric acid) as well as the whole of theacetic acid is added, and the temperature of the solution raised toabout 88 degrees, cent., after which the 300 pounds of sodium bichromate(or its equivalent in another alkali bichromate) is added to thesolution. The addition of the sodium bichromate is effected in a gradualmannen' care being taken that theseadditions should n t cause a violentrise in temperature that would result in the liquid boiling violently,th reby causing or resulting in a loss of material. While it isdesirable that the temperature should be maintained at as high a pointas possible violent ebullition and consequent foaming must be avoidedatall times. The reaction. unless controlled, is apt to be exceedinglyviolent. but inasmuch as the reaction itself is strongly exothermic, itbecomes possible to control the temperature within adesired range by theiudicious addition of the alkali bichromate. ca e being taken todistribute the latter as evenly as possible in the bath. As the reactionapproaches its close, the temperature rise after each such addition ofalkali bichromate becomes progressively less. until it flnally becomesnecessary (in general) to apply external heat in order that the reactionmay not become arrested and the alkali bichromate fail to becomecompletely reduced.

'Lack of complete reduction of the alkali bichromate is revealed by abrown color in the liquor,

whereas complete reduction results in the mixture assuming a decidedlygreen color.

When the operation is definitely complete. the resulting dye liquor willcontain an alkali sulphate, or an alkali metal salt of the acid utilizedin decomposing the bichromate com ounds. to gether with the chromiumcontents of the alkali bichromate as a carbohydric compound of chromium,that is, as a gluconate, glycolate. trihydroxy-butyrate or relatedcompound. The dyeing liquor is very weakly ionized. and even ifhydrolyzed, exerts no iniurious or dama ing efi'ect upon cellulose,itself a member of the car bohydrate family.

If desired, the sodium bichromate (or equivalent) may be dissolv'ed inwater before. mixture with the acid-sugar solution. For example. the 300pounds of sodium bichromate (or equivalent) may be dissolved in water('75 gallons) and the whole heated to 88 degreescent., whereupon theacid saccharose solution which has previously been heated toapproximately 70 degrees cent. is slowly added to the alkalibichromatesolution, care being taken that the temperature shall not rise withsufficient rapidity to cause violent ebullition and consequent loss ofmaterial. The color of the liquor at the close of the reaction should bea clear olive-green, but should it remain brown it will become necessaryto add additional quantitles of the acid-saccharine solution until the,color has become permanently green. It is essential to maintain theintermixed solutions at as high -a temperature as possible during thewhole of the reaction. The reaction is facilitated by the presence ofacetic acid, or equivalent, including saccharic acid as an equivalent.

The novel mineral dye solution thus produced may be diluted with waterin any desirable degree, so as to give various shades of green, or theycan beapplied in such a degree of concentration that even deep shadescan be secured with but a single immersion and padding of the-textilematerial. The carbohydrate compounds or chromium which make up the dyeliquor being already in an oxidized state, require no further oxidationwhen padded into the fabric. These compounds react rapidly with hotcaustic alkaiies, becoming immediately insolubilized, and without anymanifestation of bleeding" or solution of the same in the-precipitatingmedium or hot caustic bath, as is the case with most chromium salts. Thecellulose or cotton component of the textile"material, being itself acarbohydrate, does not react chemically with carbohydric compounds ofchromium, so consequently there is no tendency manifested to tender ordisintegrate the fabric as is the case when inorganic salts of chromiumare employed.

a. While the general shade of a chrome dyed fabric is markedly on theorder of green, the chromium compounds of the present invention may beintermixed with other dye materials, of which pyrolignite of iron is anexceedingly important member, thereby securing such additional shades orcolors as those denominated "Mineral Pearl, Battleship Grey", SandShades", "Hong Kong, "Khaki and Iron Buff", iron pyrolig nite beingselected for this purpose because of its chemical inertnes with regardto cellulose. The carbohydric compounds of chromium pos sess a very lowhydrogen ion concentration, consequently having no strong tendency totender fabrics as is the case with inorganic compounds of chromium, andat the same time their carbohydric acid radicals are easily replaced bythe acid radicals of sulphuric and hydrochloric acids. It is thereforepossible, without incurring danger of tendering the fabric to replace apart of the iron 'pyrolignite by such compounds as ferrous sulphate andferric sulphate, thereby lowering the cost of the mineral dye liquor andeven improving its quality in certain respects.

The following are typical minsral dye liquors based on the chromiumcarbohydrate compounds of this invention:

1. "All-mineral Pearl". 'All-mineral Battieship Grey". Aqueous solutionof carbohydrate compounds of chromium, e. g. glycolate, gluconate, etc.of chromium. Ten to twenty per cent chromic oxide equivalent.

'2. "All-mineral Khaki". All ingredients on basis of 5% oxideequivalents.

Gallons Carbohydrate compounds of chromium--- 25 Black iron liquor 37%Ferrous (or ferric) sulphate solution 37% 3. All-mineral Khaki".

' Gallons Chromium carbohydrate solution 25 Black iron liquor '15 4.Chromium Brown." Chromium carbohydrate sohition-- gallons Manganeseacetate pounds 3 The novel chromium carbohydrate compounds of thisinvention, when accompanied by aslight excess of carbohydrate reducingagents such as glucose and other aldo-hexoses, e. g. galactos'e, orketo-hexoses (e. g. fructose), exert a distinct solvent action oncertain of the so-called vat" dyestuffs, i. e. derivatives in general ofanthracene and anthraquinone bases, thereby making it possible tointroduce such dyestuffs into the mineral dye liquor, whether the latterbe composed entirely of chromium compounds or chromium compounds inadmixture with salts of iron and manganese. The introduction of "thesedyestufls into the mineral dye liquor makes possible the production of agreat variety of shades, of which the majority are very fast to alkaliand light, and possess a much greater resistance to' exposure thanstraight vat" dyes. In application, the mineral dye liquor carrying acertain proportion of "vat" dyestuil' is padded'directly on the fabric,squeezed and dried, the anthracene dyestuff being oxidized and fixed onthe cloth in an insoluble condition during the drying operation. Thechromium content of the dyed,

fabric is then insolubilined in the normal manner, 1. e. by passing thefabric through a hot bath of caustic alkali.

The dye composition of this invention may also be used in conjunctionwith the so-called sulphur dyestuifs. The sulphur dyestuffs aredissolved in the usual alkaline dye bath of sodium sulphide, care beingtaken to provide an excess of sodium sulphide with which to effect theinsolubilization of the chromium compounds deposited upon and within thefabric. In application, the fabric to be dyed is first impregnated inthe bath of chromium mineral dye liquor, then squeezed and dried. Thedried fabric is then passed through the hot sodium sulphide dye bathcontaining the sulphur dyestuffs in solution, and' the latter aredeposited upon and absorbed by the, fabric simultaneously with theinsolubilization of the chromium compounds already padded into thefabric. This operation can either be carried out in an ordinary jigger,or as a continuous operation in continuous sulphur dyeing in theconventional "box machine, or sulphur dye run.

In the claims, the words carbohydrate and carbohydric refer to thatgroup of compounds containing carbon combined with hydrogen and oxygenaccording to the formula 010-) g, in

which a: may be 5, 6 or 12, and y may be 5, 8 or 11.

What is claimed is:

1. In a mineral dye of the character described. a saccharose derivativeof the group consisting of chromium glycoiate and chromiumtri-hydroxy-butyrate.

2. A mineral dye liquor comprising an aqueoussolution of achromium saltof a carbohydric acid, said salt being formed by the oxidation of thereaction product of the hydrolysis of a polysaccharose of the groupconsisting of cane sugar,

cane sugar molasses,- beet sugar and beet sugar molasses.

-3. A mineral dye liquor comprising an aqueousvsolution of a mixture. ofa saccharose derivative 4. A mineral dye liquor comprlsing an aqueoussolution of a mixture of a saccharose derivative of the group consistinggiycolate,

and chromium tri-hydroxy-butyrate with pyrolignite of iron and sulphateof iron.

5. A mineral dye liquor comprising an aqueous solution of a mixture of asaccharose derivative of the group consisting of chromium glycolate,-

chromium gluconate and chromium tri-hydroxybutyrate with a Water solublesalt of manganese.

6. In a mineral dye of the character described, a saccharose derivativeof the group consisting of chromium glycolate, chromiumtri-hydroxybutyrate and chromium gluconate together with a vat dyestuff.

7. The steps in the method of making a mineral dye consisting inhydrolyzing a polysaccharose into a monosaccharose of the groupconsisting of keto-hexose and aldo-hexose, and completely oxidizing themonosaccharose so formed by use of an alkali bichromate.

8. The method of making a mineral dye, comprising mixing an alkalibichromate with an aqueous solution of a polysaccharide of the groupconsisting of cane sugar, cane sugar molasses, beet sugar, beet sugarmolasses, corn syrup and glucose, said aqueous solution being acidulatedby a mineral acid of the group consisting of sulphuric and hydrochloricacids, the amount of v said mineral acidbeing just suflicient todisplace the alkali metal radical and without producing a chromium saltof the acid, and with the addition of an acid of the fatty acid seriesof the group consisting of acetic and formic acids, the amount of saidfatty acid not exceeding fifty per cent by weight of the mineral acidemployed, care being taken to maintain the temperature of the reactingmixture as high as possible without undue ebullition.

9. The method of making a mineral dye, comprising hydrolyzing apolysaccharose carbohydrate of the group consisting of cane sugar, canesugar molasses, beet sugar, beet sugar molasses and corn syrup,oxidizing the hydrolyzed poly-' saccharose carbohydrate by the additionof an alkali bichromate, adding only suiflcient mineral acid of thegroup consisting of hydrochloric and sulphuric acid to the solution todisplace the alkali metal radical of the alkali bichromate, introducingan amount of a water soluble acid of the fatty acid series of the groupconsisting of acetic and formic acids, the amount of said fatty acid notexceeding one half of the amount of gether with suflicient mineral acidof the group consisting of hydrochloric and sulphuric acids to combinewith the alkali metal component, but

not sumcient to form a salt of chromium with such acid, adding theretoan acid of the fatty acid series of the group consisting of acetic andformic acids in an amount not exceeding one half of the mineral acidsemployed, forming in such mixture simultaneously chromium trioxide andcarbohydric acids, both of which unite to form a compound of chromium.

CLARENCE B. WHITE.

